Rinse rice under cold water. In a saucepan, combine rice and chicken broth, bring to a boil over medium-high heat. Reduce heat to low, cover, simmer for 15-20 minutes, fluff, then mix in cilantro and lime zest.

Pat chicken dry. In a bowl, mix chili powder, cumin, smoked paprika, garlic powder, salt, and pepper. Rub spice mix on chicken, rest for 10 minutes.

In a skillet, heat olive oil over medium-high heat. Add chicken, sear for 6-7 minutes on each side until golden and internal temperature is 165°F. Rest for 5 minutes, then slice.

Preheat broiler. On a baking sheet, toss corn with melted butter, broil for 4-5 minutes, stir, and broil an additional 3-4 minutes until charred. Mix with lime juice, Cotija, and optional Tajín.

In a bowl, whisk together sour cream (or Greek yogurt), mayonnaise, lime juice, and garlic powder. Add cayenne if desired. Adjust consistency with water or milk.

To assemble, start with a base of rice, then add sliced chicken and charred corn. Drizzle with creamy sauce.